1 #include <bits/stdc++.h>
 2 using namespace std;
 3
 4 const int maxn = 1e4+5;
 5 const int INF = 1e9;
 6
 7 vector<int> G[maxn],vertices;
 8 int p[maxn],d[maxn][3];
 9
10 void dfs(int u,int fa){
11     vertices.push_back(u);
12     p[u] = fa;
13     for(int i=0; i<G[u].size(); i++){
14         int v = G[u][i];
15         if(v!=fa) dfs(v,u);
16     }
17 }
18
19 int main(){
20     int n;
21     while(scanf("%d",&n)==1){
22         for(int i=0; i<n; i++) G[i].clear();
23         for(int i=0; i<n-1; i++){
24             int u,v;
25             scanf("%d%d",&u,&v); u--,v--;
26             G[u].push_back(v);
27             G[v].push_back(u);
28         }
29         vertices.clear();
30         dfs(0,-1);
31
32         for(int i=vertices.size()-1; i>=0; i--){
33             int u = vertices[i];
34             d[u][0] = 1; d[u][1] = 0;
35             for(int i=0; i<G[u].size(); i++){
36                 int v = G[u][i];
37                 if(v==p[u]) continue;
38                 d[u][0] += min(d[v][0],d[v][1]);
39                 d[u][1] += d[v][2];
40                 if(d[u][0]>INF) d[u][0] = INF;
41                 if(d[u][1]>INF) d[u][1] = INF;
42             }
43
44             d[u][2] = INF;
45             for(int i=0; i<G[u].size(); i++){
46                 int v = G[u][i];
47                 if(v==p[u]) continue;
48                 d[u][2] = min(d[u][2],d[u][1]-d[v][2]+d[v][0]);
49             }
50         }
51
52         printf("%d\n",min(d[0][0],d[0][2]));
53         scanf("%d",&n);
54     }
55
56 }